The present invention generally relates to material displacement apparatus and, in a preferred embodiment thereof, more particularly relates to apparatus for releasably coupling a replaceable excavating tooth point or other wear member to an associated adapter nose structure.
A variety of types of material displacement apparatus are provided with replaceable wear portions that are removably carried by larger base structures and come into abrasive, wearing contact with the material being displaced. For example, excavating tooth assemblies provided on digging equipment such as excavating buckets or the like typically comprise a relatively massive adapter portion which is suitably anchored to the forward bucket lip and has a reduced cross-section, forwardly projecting nose portion, and a replaceable tooth point having formed through a rear end thereof a pocket opening that releasably receives the adapter nose. To captively retain the point on the adapter nose, generally aligned transverse openings are formed through these interchangeable elements adjacent the rear end of the point, and a suitable connector structure is driven into and forcibly retained within the aligned openings to releasably anchor the replaceable tooth point on its associated adapter nose portion.
The connector structure typically has to be forcibly driven into the aligned tooth point and adapter nose openings using, for example, a sledge hammer. Subsequently, the inserted connector structure has to be forcibly pounded out of the point and nose openings to permit the worn point to be removed from the adapter nose and replaced. This conventional need to pound in and later pound out the connector structure can easily give rise to a safety hazard for the installing and removing personnel.
Various alternatives to pound-in connector structures have been previously proposed for use in releasably retaining a replaceable wear member, such as a tooth point, on a support structure such as an adapter nose. While these alternative connector structures desirably eliminate the need to pound a connector structure into and out of an adapter nose they typically present various other types of problems, limitations and disadvantages including, but not limited to, complexity of construction and use, undesirably high cost, and the necessity of removing the connector structure prior to removal or installation of the replaceable wear member.
A need accordingly exists for an improved wear member/support member connector structure. It is to this need that the present invention is directed.
In carrying out principles of the present invention, in accordance with a preferred embodiment thereof, specially designed excavating apparatus is provided which comprises a support structure having a forwardly projecting portion, a hollow wear member removably mountable on the forwardly projecting support structure portion to shield it from operational wear, and a rotatable connector pin assembly which is removably received in an opening in the forwardly projecting support structure portion and includes a connector pin having a longitudinal portion extending laterally outwardly from the forwardly projecting support structure portion.
The wear member, which is representatively a replaceable excavating tooth point, is rearwardly telescopable onto the forwardly projecting support structure portion, which is representatively an adapter nose, past the outwardly extending longitudinal pin portion which moves forwardly into a rear end cavity portion of the tooth point in a release/installation rotational position. With the point in place on the adapter nose, the connector pin is rotated relative to the adapter nose, without causing the pin to axially move relative thereto, to a locking rotational position thereof in which the outwardly extending longitudinal portion of the pin, illustratively both of its opposite ends, blocks removal of the tooth point. Representatively, the support structure and the wear member have opposing, alternately scalloped curved forwardly and rearwardly facing surfaces which are configured and positioned to be complementarily interlocked when the wear member is operatively mounted on the support structure.
When it is desired to remove the point, the connector pin is rotated away from its locking position to its release/installation position, still without moving the pin axially relative to the adapter nose, to terminate the blocking relationship between the outwardly extending longitudinal pin portion and the point and permit the forward removal of the tooth point from the adapter nose. Thus, a tooth point can be removed from or installed on the adapter nose without removing the connector pin assembly from the adapter nose or axially retracting or extending the outwardly projecting opposite pin ends relative to the adapter.
In a first illustrated embodiment of the overall tooth point/adapter assembly (an illustrative wear member/support structure assembly) the tooth point has spaced apart front and rear ends, a cavity extending forwardly through the rear end and configured to removably and complementarily receive the adapter nose, which representatively has a horizontally elongated elliptical cross-section, and an exterior side wall extending forwardly from the rear end and partially bounding the cavity. A recess is formed in the interior side surface of the point side wall, the recess having a first end portion opening outwardly through the rear end of the tooth point, and a second end portion disposed forwardly of the first end portion of the recess and being enlarged relative thereto in a direction parallel to the interior side surface of the exterior side wall of the point.
The previously mentioned connector pin is rotatably supported in a transverse opening in the adapter nose, in a manner preventing the pin from axially moving in response to rotation thereof, and has a longitudinal portion (representatively its opposite ends) extending outwardly from an exterior surface portion of the adapter nose. With the connector pin in a release/installation rotational position thereof the point is rearwardly telescoped onto the adapter nose in a manner causing the outwardly extending longitudinal pin portion, representatively axially offset opposite pin end tab portions, to pass forwardly into the interior point recess area. When the point is in place on the adapter nose, the connector pin is rotated to a locking rotational position thereof to thereby cause the outwardly extending longitudinal pin portion to block the forward removal of the tooth point from the adapter nose. By rotating the pin back to its release position, the point can be moved forwardly off the adapter nose with the pin still in place within the adapter nose and still projecting outwardly therefrom.
In one embodiment thereof, the connector pin assembly includes the connector pin and a hollow cartridge which rotatable receives the connector pin and is itself nonrotatably received in the adapter nose opening. Representatively, the adapter nose opening and the cartridge have complementarily noncircular cross-sections. First cooperating structures are associated with the connector pin and the cartridge and function to permit rotation of the connector pin relative to the cartridge about the pin axis, but preclude appreciable axial movement of the connector pin relative to the cartridge. Representatively, these first cooperating structures include a circumferential exterior side surface groove formed in a longitudinally intermediate portion of the pin, and a set screw extending inwardly through a side of the cartridge and slidingly received in the groove.
Preferably, second cooperating structures are also associated with the cartridge and the connector pin and function as a detent mechanism which is operable to releasably hold the connector pin in either selected one of its rotational locking and release/installation positions. Illustratively, this detent mechanism includes first and second spaced apart recesses formed in one of the cartridge and the connector pin, and a resiliently depressible detent structure carried by the other of the cartridge and the connector pin member and being releasably receivable in a selectively variable one of the first and second spaced apart recesses.
A second representatively illustrated embodiment of the tooth point/adapter assembly is similar to the first described embodiment with the exceptions that (1) a locking member is rotatably carried by the tooth point in the inner portion of the interior point recess, and (2) the outwardly extending longitudinal portion of the connector pin is configured to interlock with the locking member, and be rotatable therewith, in response to mounting of the tooth point on the adapter nose and corresponding forward movement of the outwardly extending longitudinal pin portion through the tooth point recess. When the point is in place on the adapter nose, the locking member is rotated to rotationally drive the pin to its locking position and thereby cause the outwardly extending longitudinal pin portion to interact with the locking member in a manner blocking the rearward removal of the longitudinal pin portion from the locking member and thus blocking the forward removal of the point from the adapter nose.
In a third representative embodiment of the tooth point/adapter assembly, the tooth point interior side surface recess is eliminated and replaced with a locking lug disposed on and projecting inwardly from an interior side surface of the point rearwardly of a connector opening therein, and the outwardly extending longitudinal connector pin portion has a slot therein. With the connector pin in its release/installation rotational position, the tooth point is rearwardly moved onto the adapter nose to thereby cause the point lug to pass rearwardly through and beyond the connector pin slot. The connector pin is then rotated to its locking rotational position to thereby cause its outwardly extending longitudinal portion to forwardly block the point lug and prevent the point from being forwardly removed from the adapter nose. When it is desired to remove the point from the adapter nose, the connector pin is simply rotated back to its release rotational position, and the point is forwardly removed from the adapter nose, with the point lug passing forwardly through the connector pin slot during such removal.
In a first alternate embodiment of the connector pin assembly the first cooperating structures, which permit the connector pin to be rotated relative to the cartridge without appreciable axial movement of the connector pin relative to the cartridge, include a dowel member extending through a transverse threaded hole in the cartridge, and a circumferentially extending exterior side surface groove formed on the connector pin and slidably receiving an inner end portion of the dowel. The dowel is captively retained in the cartridge by a set screw threaded into the dowel opening outwardly of the dowel.
The detent structure in this connector pin assembly embodiment includes a spring plunger transversely threaded into the cartridge and having a resiliently depressible inner end portion received in a second circumferentially extending exterior side surface groove formed on the connector pin and having depressions at its outer ends. The depressible end portion of the spring plunger is caused to snap into these openings as the connector pin is rotated to its first and second rotational detent positions.
In a second alternate embodiment of the connector pin assembly, appreciable axial movement of the rotatable connector pin relative to the cartridge is precluded by a transverse dowel carried by the cartridge and having an inner end portion slidably received in a circumferentially extending exterior side surface groove formed in the connector pin and having transverse opposite end portions extending in a first direction parallel to the length of the connector pin.
The detent structure which releasably retains the connector pin in its first and second rotational limit positions includes the dowel and a spring-loaded locking rod slidably carried within a longitudinally extending cartridge bore laterally offset from the connector pin and having an outer end portion projecting outwardly beyond an end of the cartridge. The locking rod is longitudinally movable relative to the cartridge between first and second limit positions, and is spring-biased in an outward longitudinal direction relative to the cartridge. The dowel is transversely carried by the locking rod for movement therewith.
With the connector pin in either of its two rotational detent positions the inner end portion of the dowel is received in one of the transverse connector pin groove end portions and is thereby releasably locked in one of the pin""s detent positions. To release the pin the locking rod is depressed into the cartridge to move the dowel into alignment with the pin groove portion extending between its opposite transverse end portions. With the locking rod still depressed, the pin is rotated to align its opposite transverse groove end portion with the inner end portion of the dowel. The locking rod is then released to thereby resiliently drive it back to its starting position which drives the dowel into the adjacent transverse pin groove end portion and releasably lock the connector pin in its second rotational detent position.
In a third alternate embodiment of the connector pin assembly, the first cooperating structures which preclude appreciable axial movement of the connector pin relative to the cartridge, but permit the connector pin to be rotated between its two rotational positions relative to the cartridge include a dowel extending through a threaded transverse cartridge bore and slidably received in a circumferentially extending exterior side surface groove in the connector pin, the dowel being captively retained in the cartridge by a set screw threadingly received in the transverse cartridge bore outwardly of the dowel.
The detent structure which is operative to releasably lock the connector pin in either of its two rotational limit positions relative to the cartridge includes a spring plunger threadingly received in a transverse bore in the connector pin and having a depressible end portion projecting outwardly beyond an outer side portion of the connector pin, and a circumferentially spaced pair of depressions formed in the interior side surface of the cartridge. When the connector pin is rotated to either of its limit positions the resiliently depressible end portion of the spring plunger snaps into one of these cartridge interior side surface depressions.